Auto-Generate Video Captions With AI, Free and No Watermark
File Tools Online · July 2026 · 6 min read
Most social video is watched with the sound off, which makes captions the difference between someone watching your video and someone scrolling past it. This tool uses OpenAI's Whisper AI to automatically transcribe your video and either export an SRT file or burn the captions directly into the footage — no watermark, and your video never has to be uploaded anywhere public to get it done.
How Accurate Are Auto-Generated Captions?
Whisper supports 99 languages and, on clear, well-recorded audio, reaches roughly 97% word accuracy on standard benchmarks. Real-world footage with background noise, overlapping speakers, or heavy accents will land somewhat lower than that, closer to the high-80s to low-90s percent range — still dramatically better than most free auto-caption tools, but worth reviewing before publishing anything high-stakes.
Burned-In Captions vs. SRT Files
Many platforms — TikTok, Reels, Shorts in particular — don't reliably support uploaded SRT subtitle files, which is why burned-in captions (rendered directly into the video image) remain the standard for short-form social content. This tool produces both: a standalone SRT transcript file, and a version with captions permanently burned into the video, packaged together in one ZIP.
Why Some Competitors Watermark Free Exports
Several popular caption tools give away the transcription for free but watermark the final burned-in video unless you upgrade, or cap the free tier at a short clip length. This tool doesn't watermark exports and processes the full video you upload.
How to Auto-Generate and Burn In Video Captions
- Create a free account — no credit card required.
- Go to Tools → AI Tools → Auto Video Subtitles.
- Upload your video or audio file.
- Download the ZIP containing your SRT transcript and the captioned video.
- Your original file is deleted from the server within 30 minutes.
Try it free — no credit card required
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Use Auto Video Subtitles Now →Related Reading
For more on the underlying technology, see our guides on adding automatic subtitles to any video using AI and Whisper AI transcription across 99 languages.
Frequently Asked Questions
How accurate are the auto-generated subtitles?
Whisper reaches roughly 97% word accuracy on clear, benchmark-quality audio; real-world footage with background noise or strong accents typically runs somewhat lower, so a quick review before publishing is worthwhile.
Can I get an SRT file, or does it only burn captions into the video?
Both — the output includes a standalone SRT transcript file alongside the version with captions burned directly into the video.
What languages are supported?
Whisper supports 99 languages for transcription.
Will this work for TikTok, Reels, or Shorts?
Yes — the burned-in caption version is specifically useful for these platforms, which often don't reliably display uploaded SRT files.
Are my videos kept private?
Yes, files are transferred over HTTPS, processed privately, and deleted within 30 minutes.